Yarn tensioning apparatus for tufting machines capable of making pile fabrics with repeat patterns thereon of loops of varying lengths



Dec. 17, 1968 R. ELLISON ETAL 3,416,471

YARN TENSIONING APPARATUS FOR TUFTING MACHINES CAPABLE OF MAKING FILE FABRICS WITH REPEAT PATTERNS THEREON OF LOOPS or mums LENGTHS 4 Sheets-Sheet 1 Filed Jan. 23, 1967 km ELL/5 Mmmm Plants 116w WWII/Mk) & Ana/25m; 73mg,

INVE NTORS Dec. 17, 1968 R. ELLISON L YARN TENSIONING APPARATUS FOR TUFTING MACHINES CAPABLE OF' MAKING FILE FABRICS WITH REPEAT PATTERNS THEREON OF Filed Jan. 23, 1967 LOOPS OF VARYING LENGTHS l l 21 I 7 4 Sheets-Sheet 2 1968 R. ELLISON ET 3,415,471 YARN 'rsnsxonms APPARATUS FOR TUFTING mcamss CAPABLE or mxme FILE mamas WITH REPEAT PATTERNS 'rnsnnon or LOOPS OF VARYING LENGTHS Filed Jan. 83. 1967 4 Sheets-Sheet 5 Dec. 17, 1968 R. ELLISON ETAL 3,416,471-

YARN TENSIONING APPARATUS FOR TUFTING MACHINES CAPABLE OF MAKING FILE FABRICS WITH REPEAT PATTERNS THEREON OF LOOPS OF VARYING LENGTHS Filed Jan. 25, 1967 4 Sheets-Sheet 4 "F G. 67' E 33 United. States Patent 3,416,471 YARN TENSIONING APPARATUS FOR TUFT- ING MACHINES CAPABLE OF MAKING PILE FABRICS WITH REPEAT PATTERNS THEREON 0F LOOPS OF VARYIN G LENGTHS Ronald Ellison, Norman Pickles, John Pritchard, and

Lawrence Taylor, Bastfield Mill, Blackburn, England, assignors, vto Ellison Tut'ting Machinery Limited, Blackburn, England Filed Jan. 23, 1967, Ser. No. 610,988 Claims priority, application Great Britain, Jan. 28, 1966, 3,867/ 66 2 Claims. (Cl. 112-79) ABSTRACT OF THE DISCLOSURE To provide a compact yarn tensioning and braking arrangement, a common bar, over which yarns are guided in parallel, is drilled with holes transverse to the yarn, with pistons located in the holes against which compressed air is applied when a particular yarn is to be placed under increased tension; a supply of compressed air can be readily arranged for a number of piston simultaneously to provide for pattern repeat.

The present invention concerns tufting machines for producing carpets and like pile fabrics.

An object of the present invention is to provide improved device for controlling the patterning of such fabrics.

It is known to produce a pattern of high and low loops in a carpet by sensing a pattern with a plurality of devices such as photo-cells, controlling an air valve by each photo-cell and causing each valve to operate a piston having a brake shoe which rests on a plurality of yarns to control all their tensions simultaneously. The yarns then pass through what is known as a scramble box which distributes the yarns to a corresponding number of pattern repeat locations on the carpet being formed.

Whilst this is an effective method of producing pattern repeats, it has been found that the loop length of the repeats may vary and this is thought to be due to the varying amount of elasticity in the varying lengths of yarn in the scramble box between the brake shoes and the carpet surface. .1

There has been devised a pattern repeat producing device in which the tension to be applied to each yarn is derived from a small piston individual to each yarn, the pattern repeat being effected by coupling a plurality of such pistons to each valve. By this means the length of each yarn from its piston to its associated tufting needle can be made the same, thus eliminating the possibil-' ity of producing loops of varying length.

Subject matter of the invention The tuf-ting machine for making carpets and like fabrics With a repeat pattern thereon of loops of varying length has a yarn tensioning device including individual yarn tensioners one for each yarn in the machine, and pneumatic means for actuating pistons bearing against the yarn in a plurality of such tensioners equal to the number of repeats of the pattern.

In one embodiment of the invention, a tufting machine draws a plurality of yarns from a creel, these yarns being each passed through a first hole in a metal bar mounted transversely on the machine and parallel to the line of entry of the needles into the backing fabric. Each hole is connected to a second hole extending at right angles thereto, and the second hole carries a small piston-like metal member, preferably cylindrical, with one end rounded ofl? or chamfered; alternatively a ball may be used. This piston member is free to slide in its hole and the lower end rests on its associated yarn in the first hole. The upper end is subject to pressure from an air supply delivered to it by a branched pipe, the other branches of the pipe running to pistons acting on yarns located in places such that they form repeat patterns on the base fabric.

Each branched pipe may also be connected to a valve controlling a supply of compressed air thereto, these valves being in turn controlled by sensing devices such as photocells and amplifiers, the photocells co-operating with a pattern member moved synchronously with the backing fabric, the member carrying a pattern to be reproduced several times in the width of the carpet. The sensing devices and pattern member may have action reversing means associated therewith to vary the kind of pattern repetition effected.

After leaving their piston assembly, the yarns pass over friction rollers which forward them at a rate determined by various factors including the restraining pressure exerted on them by the pistons and are then led to their needles which insert loops of varying length determined by the pressure of the pistons.

Various modifications may be made to the invention. Thus oil may be used as the pressure transmission medium instead of air. Again, the pattern sensing means may consist of electrical brushes resting on the surface of a conducting pattern member, or a punched card or tape could be used. A separate piston-and-cylinder assembly could be used for each yarn, these assemblies being fixed to a common support.

Preferably the location of the individual pistons relatively to one another and the needles is such that all the yarn paths between the pistons and needles are of substantially the same length.

Finally, each piston may be electrically controlled, a plurality of pistons equal to the number of repeats being connected to and moved by each pickup means. Valves controlling compressed air to each such piston may be the movable cores of solenoids.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a tensioning device using a cylindrical piston brake;

FIG. 2 shows a similar tensioning device but using a ball brake;

FIG. 3 shows the method of drilling a bar to hold the tension devices shown in FIGS. 1 and 3;

FIG. 4 is an arrangement of individual tensioners shown partly in section, each using an individual brake cylinder aifixed to a common bar;

FIG. 5 is an end view of the tensioners and feed rollers;

FIG. 6 shows one method of controlling a pattern repeat by air multiplying;

FIG. 7 shows a combined brake, cylinder, valve and solenoid; and

FIG. 8 shows a method of multiplying assemblies as shown in FIG. 7, electrically.

Referring to FIG. 1, there is provided a single common bar 1 having a guide hole 2 bored through it, this hole carrying a single yarn. The yarn is derived from a creel to the left of the figure and the yarn is drawn through the hole in the direction of the arrow towards the right of the figure in a manner to be described in connection with FIG. 4.

The bar also contains a plurality of drillings 3, the axes of which are at right angles to the hole 2 for the yarn. The hole 3 is provided with a thread 4 at its upper end and a pipe joint assembly is screwed into the thread. Compressed air is supplied to this particular assembly via a pipe 6, the air being under control of a patterning arrangement; in the hole 3 there is a cylindrical piston 7 with a rounded lower end, this lower end being adapted to engage a yarn passing through the hole 2.

When no pressure air is applied to the upper end of the piston 7, the yarn is drawn through the hole 2 from the creel under relatively low tension. When pressure air is applied to the pipe 6 by the pattern control arrangement, the cylinder 7 is forced downwards by the air pressure and its lower surface presses the yarn against the inner face of the hole 2, thus causing higher tension to appear on the exit side of the yarn. This increased tension causes the machine to produce a short loop of yarn by the needle through which the particular yarn concerned passes. There is one piston 7 and air supply 6 for each yarn passing through the bar 1 and in order to obtain the necessarily close spacing of the yarn paths through the bar 1, the holes '3 are staggered from front to back of the bar as shown in FIG. 3. The front end of the bar is shown as being the lower side in FIG. 3 so the yarn enters at the top of the bar and leaves at the bottom.

FIG. 2 shows an alternative form of yarn brake. The fitting 5 is the same as before, together with an air supply pipe 6. The main difference is that in the hole 3 there is a ball 8, the hole being of such dimensions that the ball slides with as little clearance as possible in the hole. This arrangement is slightly cheaper than that shown in FIG. 1 but the piston end is preferred in that its braking effect is less variable than that exerted by a ball.

Turning now to FIGS. 4 and 5 a common bar is here provided, the bar being seen from the end at right angles to the traverse of the yarn. Above and below the bar there are a number of individual brake assemblies, one of which is shown in section at 11. As before, the brake assemblies are staggered from front to back of the bar so as to obtain a maximum number of yarns for a given assembly width.

On the top and bottom of the bar 10 is a further bar 12, 13, held in position by support and spacing members 22, these bars 12, 13 being drilled to act as supporting members for the brake assemblies 11. Each of these assemblies comprises a cylinder 14, a piston 15 having a seal 15a and piston rod 16, a retractor spring 17 and a yarn brake shoe 15b. Each brake assembly has a stepped end 11a of slightly smaller diameter, this end being adapted to fit into the bar 12 or 13' where it is held with a set screw 21. The upper end of each cylinder is connected to a joint member 18, with compressed air entry pipe 19 and a connection to another valve 20. The valve 20 effects a pattern repeat which is described later and is operated simultaneously with the assembly shown in FIG. 4. Each yarn such as 23 passes over the surface of the brake plate 10 between spacer pins 25, 26, the pins for the cylinder shown in section being displaced slightly from the pins shown for the adjacent cylinder shown in full view so that each cylinder and brake acts on one yarn only. The cylinder assemblies below the bar 10 are also staggered with respect to the cylinders above the bar so that four yarns are braked by the particular cylinders shown in the drawing, with minimum possible sideways spacing between the yarns. The bars 12, 13 carry as many cylinders as there are yarns to be woven by the machine.

It will be seen that cylinder 30 is connected by means of a pipe 31 to a controllable valve 32, this valve being actuated by means of a solenoid '33. There is also another pipe 34 which continues to the next cylinder along the bar .10. The pipe 34 is connected to pipe 31 in a T-junction 36 and connects to the next cylinder similar to 30 which repeats the pattern woven by the yarn under control of the cylinder 30. A further connection is taken from this next cylinder to the next and so on, until the whole number of pattern repeats is effected. Similar connections from valves such as 32 are taken to all of the cylinders shown in the figure, from dilferent valves, each controlled by a dritferent solenoid and pattern multiples of pipes similar to that shown in connection with cylinder 30 are also fitted to each of the other cylinders. Pattern multiplying takes place in a direction along the bar 10 at right angles to the plane of the paper.

When the yarn leaves the bar 10, it traverses a guide eye 37 and then passes round two rollers 40, 41 these two rollers being separated so that the yarn does not pass through a nip between them. The surfaces of the rollers are smooth, so that the yarn can slip thereon. Both rollers are driven at a speed sufficient to supply enough yarn to the needles so that all the loops inserted by the needles are long ones. However, when the brake for one yarn is applied to the yarn, some slip takes place on the surfaces of the rollers 40, 41, so that the needle associated with this particular yarn makes a short loop instead of a long one. The yarn from roller 41 passes in the direction 42 to the needles of the machine, which are of a conventional pattern.

Referring to FIG. 6, it will be seen that the valve 32 is connected by a pipe 31 to a cylinder assembly 30. The valve is controlled by a solenoid 33 and it is supplied with pressure air via a pipe (not shown). The valve also has an exhaust port so that after de-energisation of its operating solenoid the valve returns to its normal position and allows air to escape from the cylinders it controls, the pistons of which are removed from their associated yarns by the springs within the cylinders. The cylinder 30 is connected by another pipe to the adjacent cylinder 30a, then to a further cylinder 30b and so on, there being a number of cylinders across the machine equal to the number of repeats. A similar group of cylinders is equipped with a similar valve and solenoid for the next set of yarns to be controlled and so on, these valves then extending across the width of a single pattern repeat in each case.

Although the invention has so far been described in connection with a common bar used in drilled form to provide a series of yarn brakes, or in connection with a bar such as 10 in FIG. 4, on to which a plurality of cylinder brake assemblies act, all the cylinders connected with one particular yarn repeat being multipled by means of air pipes and actuated by a single solenoid, a further variation is possible. Thus in FIG. 7, a cylinder 50 is provided, on to which a valve 51 individual to this particular cylinder is fixed. The valve is actuated by a solenoid 52, so that each brake is actuated by its own valve and each valve by its own solenoid. Compressed air enters at pipe 53 and is exhausted by pipe 54. All the cylinder, valve and solenoid assemblies similar to that shown in this figure are assembled on a bar such as 10, FIG. 4 and in a similar arrangement. One end of each solenoid is connected to earth and the other end to a terminal 55. Pattern repeats are effected by inter-connecting electrically all the terminals 55 across the width of the machine, the solenoids being connected in their repeat groups to contacts of relays operated by the pickup mechanism. Such an arrangement gives by far the most flexible form of machine, since by merely altering a number of wires, the machine can be adapted to do 2, 3, 4, 5 or more repeats of a single pattern across the whole width of the woven fabric.

In FIG. 8, a bar 60 of insulating material is shown, having a number of clips 61 corresponding in number and position to the number of terminals 55 located across the width of the machine. There are also a number of other clips 62, these being equal to the number of yarns in each repeat. The bar with its clips is located, when in use on the machine, so that all the clips 61 engage with all the terminals 55. The terminals 62 engage with relay contacts of the pattern detecting mechanism which control the operation of the solenoids. A set of multiple Wires 63 inter-connects the clips 62 and clips 61; if the number of pattern repeats is to be changed, all that is required is to supply another bar 60 with different connections 63. One bar is then removed from the machine and the next biar plugged in so that any particular machine may be converted to operate any required number of repeats of pattern. Again, if a machine is built so as to produce fabric say 60 inches wide, it is quite easy to convert the machine to operate on a narrower fabric by applying a bar '60 with clips suitably positioned and inter-connected so as to actuate less than the total number of yarn brakes provided on the machine.

We claim:

1. A tufting machine including loop forming means for making carpets and like pile fabrics with a repeat pattern thereon of loops of varying length and having means for selectively applying tension to selected yarns, said machine comprising a common bar;

a plurality of parallel guide holes drilled through said bar for guiding a plurality of yarns feeding through said bar to said loop forming means;

said common bar having cylindrical holes equal in number to said guide holes and extending into said common bar for intersection with said guide holes;

a brake piston means slidable in each said cylindrical hole for engagement with respective yarns feeding through said guide holes to said loop forming means for selectively applying tension to said yarns;

compressed air means connected to each said cylindrical hole for pressing said piston means against its respective yarn;

and means for controlling the air applied to each said piston whereby loops of varying lengths are obtained commensurate with the amount of air applied to respective pistons.

2. Apparatus according to claim 1, wherein adjacent holes are located on said common bar ofiset with respect to each other in the direction of the path of the yarn over said common bar.

References Cited UNITED STATES PATENTS 1,860,072 5/ 1932 Braudes 112-79 2,862,465 12/1958 Card 112--7'9.6 X 2,971,722 2/1961 Penman 11279.6 X 3,067,701 12/1962 Wilcox 112-79 3,334,601 8/ 19 67 Ellison et al. 112-79.6

FOREIGN PATENTS 1,011,496 12/ 1965 Great Britain.

HERBERT F. ROSS, Primary Examiner.

U.S. C1. X.R. 112410; 139-7 

